When you're having sex with a chick that you know doesn't like anal and attempt to sneak it in her ass. She pulls her ass back, shakes her head no and makes sounds like a dolphin, "Ahhkaa Ahhkaa Ahhka"...hence the dolphin tail.
Man, last night I was fucking this hot chick Tina, I attempted to hit the back door and she cock blocked me with a Dolphin Tail!
by Tina Does Dallas November 12, 2012
When your fucking a chick, you pull out before you cum and as your cumming you slap her in the face with your cock.
by Brain Crabb September 23, 2006
Similar to downhill skiing, a girl grabs a genital on both sides of her and preceds to jerk them of like she was skiing. The dolphin tail Is the same thing but she adds her feet into it so she’s jerking another dude off with her feet.
Dude! Last night me, Billy, and Leroy had this girl doing the dolphin tail on us. It was so sexy we all nutted whithin 2 minuets.
by OfficiallyRealFunny March 29, 2018